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Design of frequency filters with non-traditionally combined active elements
Danyi, Ivo ; Koton, Jaroslav (referee) ; Jeřábek, Jan (advisor)
This paper discusses the frequency second-order filters that work in the current mode. As active elements are used VDTA (voltage differential transconductance amplifier) and CCTA (Current Conveyor Transconductance Amplifier) design method as a method is used to graph of signal flow. They are designed and analyzed four frequency filters. The first uses only one element VDTA and is a multifunctional frequency-controllable frequency filter of the second order. The second is composed of two elements, is VDTA fully controllable multifunctional frequency filter of the second order. The third uses one element CCTA represents a multifunctional frequency filter of the second order without control. The fourth element uses a single CCTA and VDTA and is a multifunctional frequency-controlled frequency filter of the second order. All frequency filters are subjec- ted to sensitivity analysis and simulated for ideal and non-ideal active element. Second circuit wiring with two VDTA elements is realized and analyzed the characteristics of this filter.
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Analysis of filter structures with controllable amplifiers
Pánek, David ; Langhammer, Lukáš (referee) ; Polák, Josef (advisor)
This bachelor thesis is focused on simulations and practical realizations of already existing frequency filters with modern active components in current mode. New simulation ABM model (Analog Behavioral Model) of DACA (Digital Adjustable Current Amplifier) element was used in the simulations. The first part informs about problems concerning analogue frequency filters. The second part deals with used active components - DACA (Digital Adjustable Current Amplifier), MO-CF (Multiple Output Current Follower), BOTA (Balanced transconductance amplifier) and UCC (universal current conveyor). Four circuits have been chosen and implemented into PCB (printed circuit board) on the basis of simulation results. The first circuit tunes the quality factor with help of DACA component. The second circuit tunes the natural frequency and quality factor with help of DACA components. The third and the fourth circuits are simulated and implemented in differential and also in single ended forms. These circuits tune the natural frequency with help of the same set of current amplification by DACA components. The last part is summary of simulation’s and practical measurement‘s result of this project.
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Design of frequency filters with nontraditional active elements
Jarník, Lukáš ; Herencsár, Norbert (referee) ; Jeřábek, Jan (advisor)
Main topic of this semestral thesis is to design frequency filters with unusual active elements. They are presented active elements as are current conveyors (GCC), voltage conveyors (GVC), transconductance amplifiers (OTA, CFTA), which operate in current mode. Further the thesis contains six designed and simulated circuits with active elements (GCC), (CFTA), (OTA) and (GVC), which are based on according full admittance network. One designed was practically implemented and experimentally verified.
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Linear system stability analysis
Jelen, Michal ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
This bachelor’s thesis will be dealing with stability analysis of linear systems. In theoretical part will be mentioned stability and its conditions, stability criteria, their partition to groups and description of each criterion. In practical part will be chosen one stability criterion which will be working with afterwards. As examined circuit will be a filter with current conveyors as active elements which will be obtained a characteristic multinomial from. There will be working with transmittion functions of single and double pole model in examples. It will be created a computer programme which will enable an automatization of Routh’s stability criterion and plot graphical outputs in dependence on input parameters and their values.
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Design of the Rail-to-Rail current conveyor in CMOS technology
Hudzik, Martin ; Kledrowetz, Vilém (referee) ; Prokop, Roman (advisor)
Master’s thesis deals with design of rail-to-rail second generation current conveyor in CMOS technology. Describes principles of function of different generations of current conveyors, as well as the basic principle of design of second generation current conveyor based on operational amplifier. Addresses circuit topology of input rail-to-rail stage and class AB output stage. The objective of this thesis is to design, characterize performance and create layout of second generation current conveyor with input common mode voltage rail-to-rail capability in ONSemi I3T25 technology.
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Behavioral models of active elements with possibility of independent multi-parameter control
Novotný, Jakub ; Hruboš, Zdeněk (referee) ; Šotner, Roman (advisor)
This thesis is focused on behavioral modelling of active elements with independent multi-parameter electronic control using comercially available components. In a first part of the thesis, CVDIBA, CVDOBA, CVCC and OC elements are discussed. The functionality is verified by simulations using OrCAD PSpice. Used components are diamond transistor OPA860, variable gain amplifier LMH6505, differencing amplifier AD830, low distortion differential driver AD8138, current conveyor EL2082 and current mode four quadrant multiplier EL4083. Four active elements are further built on PCB and measured. Some applications like low pass filter, high pass filter, all pass filter and reconfigurable filter.
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Active controllable frequency filter in current mode
Zbořil, Jan ; Petržela, Jiří (referee) ; Brančík, Lubomír (advisor)
The aiml of this work is to study the principles controllable frequency filters in the current mode. Is realized multifuctional current filter. Summarizes the general characteristic of the current components. Work focuses mainly on current conveyors CCII. Circuit is used here EL 2082 as a basic building element. The second chapter discussed the characteristics of filters, the third contains a description of the basic active circuit. The next chapter deals with the simulation, and the last presents the measured results.
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Low voltage low power current conveyor CCII
Kadaňka, Petr ; Vávra, Jiří (referee) ; Khateb, Fabian (advisor)
This paper is focused on comparing CCIIs by their construction principle. It researchs differences between gate-driven and bulk-driven approach, and between design based on current mirrors or operational amplifier. Designed current conveyor functionality is verified by SPICE simulation. Main objective of this work is to obtain current conveyor with lowest possible supply voltage and minimal power consumption.
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Frequency Filters with Current Active Elements
Jeřábek, Jan ; Ondráček,, Oldřich (referee) ; Kolka, Zdeněk (referee) ; Vrba, Kamil (advisor)
This doctoral thesis is focused mainly on research of new current active elements and their applications in frequency filters suitable for current-mode. Work is focused on design of new filtering structures suitable for traditional single-ended signal processing and also on structures suitable for fully-differential applications. The thesis contains three designed general conceptions of KHN-type second-order filters. Adjustability of quality factor and pole frequency is provided by controllable current amplifiers that are placed properly in designed structures. Structures also contain second-generation current conveyors, multiple-output current followers, transconductance amplifiers and their fully-differential equivalents. There are lot of possible solutions that could be obtained from general structures, some of them are presented in the work. The thesis also presents several multifunctional and also single-purpose filtering structures of second-order and two variants of n-th order synthetic elements which are suitable to realize higher order filters both in single ended and fully differential type. In each case, functionality of new solutions is verified by simulations and in several cases also by real measurement.
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Synthesis and Analysis of Circuits with Modern Active Elements
Koton, Jaroslav ; Vrba, Kamil (advisor)
The dissertation thesis deals with the synthesis and design of active frequency filters using current (CC) and voltage (VC) conveyors, or current active elements CMI (Current Mirror and Inverter), MCMI (Multi-output CMI) and PCA (Programmable Current Amplifier). As introduction, these active elements are described as suitable for the design of the circuits working in the voltage-, current,- ,and mixed-mode, or in pure current-mode speaking about the current active elements. The new frequency filter structures presented in this thesis using the above mentioned active elements were designed by the generalized autonomous circuit method, transformation cells and signal flow-graph theory. The generalized autonomous circuit method is based on full admittance network to which generalized active elements are connected. The described admittance networks can be used for other active elements. The next method is based on the transformation cells that subsequently are used for the design of synthetic elements with higher-order imittance. Original conditions for the design of such blocks are given that lead to maximal simplicity of the final structure with minimal number of passive and active elements. For effective usage of another method utilizing signal flow-graphs, new reduced graphs of chosen active elements are given. Their usage leads to direct function blocks synthesis with required properties. The functionality and behavior of chosen circuit solutions have been verified by analyses in simulation programs. The active elements were simulated by the universal current conveyor (UCC) or universal voltage conveyors (UVC) that were designed at the FEEC, BUT in cooperation with AMI Semiconductor Design Centre Brno with the CMOS 0.35 m technology. These active elements have been also used for the realization of chosen filter structures. The experimental measurements were performed in the in the frequency range 10 KHz to 100 MHz.
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